Reference is made to applicants' copending U.S. Application Ser. No. 010,596 for "A Probe For Ultrasonic-Echo Planigraphic Imaging Apparatus," filed on Feb. 7, 1979. That application is directed to similar subject matter.
This invention relates to an ultrasonic transducer probe which may be used in injecting a cannula through a region of the body of a patient to be diagnosed, e.g. in a biopsy.
In a biopsy, tissues or body fluids may be extracted from the kidney, liver and other internal body organs by means of a suitable cannula for diagnostic purposes. Also in the X-ray angiography, a cannula with an injector is pierced into blood vessels and the like to examine morbid changes in a brain, heart, abdominal organs, etc., by injecting a contrast medium. Moreover, amniotic fluid may be extracted from the uterus of a pregnant woman for diagnostic purposes, or blood or medication may be injected into a fetal body.
In all these cases, it is very important to prevent undue damage to essential organs or wrong extraction of tissues.
Accordingly, there is known an apparatus or a combination of an ultrasonic diagnostic apparatus and a cannula in which a transducer element is provided for a cannula guide means, whereby an ultrasonic beam is transmitted into the body of a patient to be examined. With this combination, a sectional image of the interior of the body can be obtained by reproducing the ultrasonic-echo pulses of the beam on a picture screen, and the cannula can be inserted into the body while the positional relationship between the cannula and the internal region to be examined is being observed (U.S. Pat. No. 4,108,165).
In addition, there is known an apparatus in which a tapered cannula guide slot is bored in a carrier of an ultrasonic probe having a plurality of ultrasonic transducer elements arranged thereon. With this apparatus the movement of the cannula can be observed by watching a sectional planar image in the body of a patient. When the ultrasonic transducer elements are driven successively, the direction of the cannula can be optionally selected within a fixed range (U.S. Pat. No. 4,029,084).
Naturally, the cannula to be injected into the patient body is required to be properly sterilized by a suitable method before use. When injecting the cannula into the patient body by using one of the aforesaid prior art ultrasonic transducer probes, however, the cannula will be brought into contact with the inside wall of the cannula guide slot bored through the carrier of the ultrasonic probe, so that the carrier itself will also be required to be disinfected before each use.
Such disinfection of the carrier is generally carried out by a gas sterilization method in which an antiseptic gas is blown upon the carrier so that the gas may be introduced through very small gaps formed at the joint portions of the carrier body 2 or the joint portions between the carrier body and the individual ultrasonic transducer elements. This gas sterilization deteriorates the adhesive strength of an adhesive used for these joint portions and causes exfoliation at these joints. Thus, by repeating such disinfection many times, the components held by the carrier body of the ultrasonic transducer probe may be damaged, and the life of the probe may be shortened. Moreover, in making examinations of several cases by means of a cannula, the carrier body of the probe must be disinfected for each patient. Furthermore, the ultrasonic transducer probe is too complicated in shape to be properly sterilized by gas disinfection.